Standardized Tests Require a Curve?

I'm not afraid of standardized tests because the results are always curved and manipulated to achieve a predetermined goal (the Bell Curve is alive and well).

Why does a curve need to be determined before providing the results to the public?
Some students don't test well;  some teachers don't teach well.  And vice versa...  
Want to make the tests more meaningful?  Make them voluntary and get rid of the curve.